Quote:
Originally Posted by matt
However, the Astrodons are not parfocal (at least not on the nights I've used them) and the light throughput is about the same as the Astronomiks...at least with the C9.25 working at around 8000mm fl. It might be a different story using the aperture and focal length of Anthony's scope? I wouldn't know  |
I wouldn't be too concerned about parfocal claims. I've always had to re-adjust focus between colour channels - moreso when the object is down low or if the seeing is not "excellent".
I always take an extra 5-10 seconds between switching channels to ensure the focus is as sharp as i can get it in the limited timeframe.